1. Field of the Invention
The present invention relates to a laser patterning apparatus. More particularly, the present invention relates to a laser patterning apparatus for handling a donor film and improving compression uniformity and transfer characteristics between the donor film and an acceptor substrate.
2. Description of the Related Art
A laser induced thermal imaging (LITI) method is a transfer method using laser light, and includes a donor substrate and an acceptor substrate.
Laser light is absorbed into a light to heat conversion (LTHC) layer of the donor substrate to be converted to heat energy, and a transfer layer of the donor substrate is transferred to the acceptor substrate by the heat energy. Because the transfer layer is transferred to the acceptor substrate, a desired image is formed in the acceptor substrate.
In more detail, the LITI method is performed as follows. After the acceptor substrate is positioned on a stage, the donor substrate (or donor film) is laminated on the acceptor substrate. One surface of the donor film is covered with a transfer layer that is made of a material for transferring.
When laminating, bubbles between the donor film and the acceptor substrate are removed using a roller. The laminated donor film is adsorbed and fixed by a vacuum groove of a chuck.
By providing a shielding mask on the donor film and radiating laser light to the shielding mask, in a portion in the donor film that receives the laser light, light is converted to heat energy to transfer the transfer layer on the donor film to the acceptor substrate, and in a portion that does not receive laser light, the transfer layer is maintained on the donor film.
After a transfer operation is completed, by removing the laminated donor film and shielding mask, the transfer layer that is transferred on the acceptor substrate forms an image of the same (or substantially the same) pattern as that of the shielding mask.
The donor film should be aligned and compressed on the acceptor substrate, but because the donor film has flexibility, the donor film should not be handled when being maintained in a flat plate shape.
Further, bubbles remaining between the donor film and the acceptor substrate are removed by being temporarily compressed to the acceptor substrate with the roller. Therefore, during a transfer process of radiating laser light, the donor film does not continuously receive a compression force acting on the acceptor substrate. As such, compression uniformity between the donor film and the acceptor substrate is lowered and transfer characteristics therebetween are deteriorated.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the invention and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.